Super-resolution is put forward for the fact that the resolution of the current video signal source is lower than the displayable resolution of a high-definition television (HDTV). The super-resolution technology is to output an image, which is more suitable to be displayed on a full high definition (FHD) liquid crystal display (LCD) TV, by stretching, comparing and correcting an initial image, and hence enhance the virtual clarity. Compared with the case that a common LCD TV is only to simply stretch and amplify a standard-definition (SD) signal to a high-definition (HD) screen, the super-resolution technology has more prominent display details and changes people's impression that the watching of a wired DVD on an HDTV is not so good as on a low-definition television (LDTV).
The resolution of image, also referred to as definition and resolving power, refers to the number of pixels capable of being displayed on a display. When the number of pixels on the display is larger, the image is finer. An HR image has high pixel density, can provide rich detail information, and can more accurately and meticulously describe an objective scene. The HR images are widely used in the information age and have very important applications in the fields such as satellite remote sensing images, video security monitoring, military detection aerial photography, medical digital imaging and video standard conversion.
Facial metamorphosis is a specific area super-resolution technology for generating HR output from low-resolution (LR) input. An LR image is obtained by the downsampling and linear convolution of an HR image. The metamorphosis technology may be construed as the reconstruction of high-frequency details. The current super-resolution technology is rarely relevant to facial metamorphosis.